leds: disallow /sys/class/leds/*:multi:* for now

All the LEDs in the queue are RGB, so they should not use multi for
their color.

Make sure we don't add such LED by mistake (and make it part of ABI).
Signed-off-by: Pavel Machek <pavel@ucw.cz>

drivers/leds/led-core.c

@@ -425,6 +425,10 @@ int led_compose_name(struct device *dev, struct led_init_data *init_data,
 	struct fwnode_handle *fwnode = init_data->fwnode;
 	const char *devicename = init_data->devicename;
 
+	/* We want to label LEDs that can produce full range of colors
+	 * as RGB, not multicolor */
+	BUG_ON(props.color == LED_COLOR_ID_MULTI);
+
 	if (!led_classdev_name)
 		return -EINVAL;